Webinar 53
GIS and Safety at the New York State Department of Transportation (NYSDOT)

September 4, 2024

Summary of the Federal Highway Administration’s Quarterly Webinar

The Federal Highway Administration (FHWA) promotes geographic information systems (GIS) as a means to manage and improve transportation systems more effectively. One of the ways that FHWA does this is through its GIS in Transportation program,¹ which identifies timely and critical GIS issues and topics in transportation and connects transportation agencies with available resources and best practices. The webinar summarized here is part of a quarterly series organized through the GIS in Transportation program.

Robert Zitowsky, Senior Transportation Analyst, Highway Safety Bureau, NYSDOT, presented on the history of GIS and Safety at the NYSDOT. This history started with the development of an early GIS Accident Location Information system (ALIS) in the 70’s, which relied on reference markers. Challenges with this legacy system included the lack of precision of the reference markers, the inability to determine facility type, and that the system was not integrated with other data systems such as the New York state roadway data, which uses milepoints. This led to the adoption of the ESRI’s Roads & Highways linear referencing system (LRS), which integrates with other data systems, and the development of the Crash Location and Engineering Analysis Repository (CLEAR). The CLEAR system consists of several applications including a Crash Data Viewer, CLEAR Safety, and CLEAR Interactive Crash Editor. The system also includes analysis layers for Highway Safety Manual (HSM) screening. The presenter gave a demonstration of the CLEAR Safety application. CLEAR components are mostly for internal use by NY state employees and contractors.

A recording of the webinar is available. Please use passcode *NZ**6IW to access it.

Questions & Answers

What percentage of the crashes and fatalities happen in densely populated areas, such as New York City?
The presenter does not know what breakdown is by region. The type of crashes is different. New York City has mostly pedestrian and bicycle crashes and the upstate crashes are more of the “run off the road” type crashes.

What platform or other road inventory systems does CLEAR connect to?
ESRI Roads and Highways Tool

Do you have issues where the crash narrative and latitude/longitude location do not align?
Absolutely, which is why we have our interactive crash editor. We can make the edits in that tool so the crash location is corrected.

In the calculation of Excess Crashes using Empirical Bayes (EB) Method, you used safety performance functions (SPFs). Were there any problems with the limited coverage of MIRE (Model Inventory of Roadway Elements) attributes to use SPFs in the LRS system?
The speaker does not know. The system relies on inputs that were put in there as defaults. MIRE a lot of elements are collected and by 2026 we will have them for all public roads.

How many staff do you have that are doing crash data cleanup using the Editor?
There are quite a few. In New York State DOT we have safety evaluation engineers in our 11 geographic regions, and they have access to make those changes. In the main office we have six people who have access to make the changes. In DMV they also collect crash data and are able to make changes.

What kinds of training do you offer? Is it in person, web-based, and do you have materials people can reference?
The training will be largely videos. The crash analysis toolbox already has videos available, and we recently received a grant to update those videos. There is also in-app Help and FAQ, and there are tool tips when the user hovers over a tool.

How did you create the geometries of the intersections?
Their intersection layer has a 100-foot buffer around the intersections. Their vendor, VHB, determined that if a crash occurred within this buffer the crash might be related to the intersection. The intersection geometry is 100 feet from the intersection center point and is the width of each roadway associated with the intersection.

Is CLEAR Safety interface developed, maintained and supported by in-house resources, or a contractor/vendor?
The contractor was VHB. They worked for NYSDOT on the previous ALIS (Autonomic Logistics Information System) system as well. They build the CLEAR system and also build systems for Connecticut, Massachusetts, and other states. It is based on ESRI technology and SQL Server. ESRI’s experience builder was used in the application creation.

Very slick tool. How does the tool account for the total CMF when an engineer adds multiple countermeasures on segment? Multiplied together?
Great question but the speaker does not know the answer.

Is there an export data feature for students and academic use?
CLEAR is only available to NYS government users and contractors working on government contracts. People could put FOI request and get the data to use for one’s own purposes. There is no public version of CLEAR at this time.

How was switching ALEC from Silverlight to a new platform? How was that process? Was there a lot of work involved?
Building this solution took years to coordinate stakeholders and the like. It was released once the Silverlight version no longer worked. Even with this version we had an issue with the API that needed to be upgraded. This always needs to be tweaked.

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